An Iowa couple say they were told by their lawyer to return the baby they planned to adopt to his birth mother. They did so—and then saw their worst nightmare occur five weeks later, when the not-yet four-month-old boy died from “abusive head trauma.”

Rachel and Heidi McFarland have now sued their adoption attorney, Jason Rieper, for malpractice. They contend he didn’t get permission for the adoption from the baby’s mother in a timely manner and failed to help them convey their concerns about the baby’s welfare to the proper authorities, reports the Des Moines Register.

The birth mother, Markeya Atkins, 16, is not accused of any wrongdoing but the boy’s father, Drew James Weehler-Smith, 17, is now charged with first-degree murder.

Atkins had let him babysit the infant while she ran some errands on April 22 and found the baby unresponsive when she returned approximately an hour later, according to authorities.

Rieper told WHO before the suit was filed that he couldn’t discuss the case due to attorney-client privilege and the fact that he might be called as a witness at a criminal trial. However, he said the adoption was complicated because both of the baby’s parents are minors.